Electric foul detector for bowling alleys



Sept. 10, 1940- A. J. GLENDENNING ET AL 2,214,274

ELECTRIC FOUL DETECTOR FOR BOWLING ALLEYS 7 Filed Jan. 15, 1940 2 Sheets-Sheet 1 'A. J. GLENDENNING ET AL ELECTRIC FOUL DETECTOR FOR BONLING ALLBYS 2 Sheets-Sheet 2 Filed Jan; 15, 1940 INVENTORS A6. 63 /55 k/ GAE/VDE/Y/Y/A' -1 .5

Patented Sept. 10, 1940 UNITED, STATES PATENT OFFICE ELECTRIC FOUL DETEGTORFOR BOWL- ING ALLEYS Ames J. Glendenning and George S. Dunlap, EstesParhColo.

Application January, 1940, Serial No. 313,814

2 Claim.

This invention relates to an electrically operquire the manual closing of electrical contacts 10 or the actuation of any moving or mechanical parts whatsoever; and which can be quickly and easily installed on present alleys without requiring any changes of any nature in the construction thereof.

15 Other objects and advantages reside in the de-.

tail construction of the invention, which is designed for simplicity, economy, and efliciency.

These will become more apparent from the fol-.

lowing description.

invention reference is had to the accompanying drawings which form a part hereof. Like numerals refer to like parts in all views of the draw lugs and throughout the description. 25 In the drawings:

Fig. 1 is a fragmentary plan view of the foul line portion of a pair of typical bowling alleys, illustrating the relative positions of the actuating members of the improved foul indicating device. 30 Fig. 2 is an enlarged longitudinal section through the foul line of an alley, taken on the line 2-2, Fig. l;

Fig. 3 is a simplified circuit diagram illustrat ing the electrical circuits between the operating 85 elements of the device.

Fig.4 is a circuit diagram of the circuits employed in the foul signal amplifier and relay box of the indicator.

1 Fig. 5 is a similar diagram illustrating the air- 40 cuits employed in the oscillator for furnishing amplified oscillating current to theidevice.

In Fig. 1 of the drawings typical parts of a bowling alley are indicated by numerals as follows: alley bed l0, runway H, foul line strip I2,

45 gutters l3, and sidewall M. The usual alley is supported from a suitable sub-floor I5, which may be on wooden leveling stringers I6. The

foul line strip 12 consists oia strip of dark'colored fiber or wood which is mortised into the sur- 5 face of the alley to divide the polished surface of the alley bed ill from the runway II.

To apply the improved foul indicator to an alley, the usual foul line strip I2 is removed,

a first electrical pickup conductor i1, consisting 55 of a copper wire or copper strip is laid in the 4 bottom of the strip receiving mortise, as illustrated in Fig. 2. The foul strip I2 is then replaced" over the pickup conductor and brought flush with the alley floor. The pickup conduc- I tor. could ii desired, be incorporated on or with- 5 in a special ioul stripbut is more cheaply and easily; installed as an independent member held in place in the mortise by the usual foul strip.

A second pickup conductor i8 is placed beneath the. alley bed parallel to the foul strip 10 i2 approximately six inches ahead of it. There may bemore' than one of these, placed approkimatelyisix inches apart and as far down the alleyxas necessary, to detect a foul-having been made ahead of the foul'line. l8

An"energizing plate I8 is positioned beneath the runway I I, preferably between the first and second leveling stringers. I6 just back of the foul strip l2. 'Ihe'fenergizingplate may beiormed In the following detailed description of the in any desired mannerl to produce-a metallic 20 electrical conducting" areaL 'It'may be a metalpickup conductors l1 and I8 extend only the 9,5-

width ofeach alley bed. This device will work without plate l9 and in some installations may be installed without it since it is connected to earth ground ,and' the. ground may act as an energizer.

In case the indicator is being installed on prescut alleys the second pickup conductor l8 and the energizingplate 19 can be pushed between.

the alley bed and the sub-floor l5. Wooden clamping strips 20 canthen bej'forced beneath the plate and the conductor-to clampv them 5 tightly against the bottom of the alley bed as shown in Fig.12. 1 g

The device is operated by constantly impressing a high. frequency oscillating current on the energizing plate. Since theenergizing plate is 40 grounded, the impressed current is inrelation to chassis. potential. and notearth ground. This current flows to and is picked up bythe pickup conductors J1 and i8. When a bowler stands over the energizing plate, this current is impressed on his body and whenhis foot passes over the that pickup conductor ll at the foul line the bowler's body acts to shunt a small flow of current; through body capacity, to the pickup conductor ll. This increase in current is amplifled sumcientlyto energize the solenoid of a relay for closing a signal'circuit t'o-give anaudlble or visible signal that a foul has been conRf-g: mltted. A foul will be committed even though the foul are connected together by a bridging conductor line is not touched, should the bowler allow his hand or other part of his body to touch the alley bed ahead of the foul line. In such a case the current flow to the second pickup conductor I8 will be increased and since both conductors 2|, this will have the same effect on the operation of the signal circuit. A signal conductor 28 leads from each set of pickup conductors. The signal conductors are encased in metallic tubing or shielding 29 to prevent capacity interference at any point other than the foul line. 7

Any suitable circuits may be employed for furnishing the oscillating current and for translating the electrical impulses received by the pickup conductors into sensible signal means.

In this embodiment a relay box 22, a signal amplifying set 23, an electric bell 24, and a signal lamp 25 are employed for each alley. Relays in the boxes 22 control the bells and lamps through bell circuits 26 and lamp circuits 21, respectively.

In respect to chassis potential of the device. Current is impressed 0n the energizing plate l9 from a suitable amplifying oscillator set 30 through an energizing lead 3| which is grounded as indicated at 32 to establish a zero potential in relation to earth ground in order to conform with wiring regulations. The shielding 29 is grounded to the chassis of the device by means of a ground lead 31.

Direct current for the bias and plates of the tubes of the sets 23 and 30 is supplied by means of rectifying power packs 33 and 34, respectively, of the usual construction. Alternating current at reduced voltage for operating the tube filaments, the relays and the bells is supplied by a suitable transformer 35. Current for the power packs, transformer, and lamp circuits is received from the regular H0 v. house current as indicated at 3B.

The amplifying oscillator circuit is standard for supplying an oscillating frequency in the high audio range. Briefly, it consists of a vacuum tube 38, which with its associated circuit acts as an oscillator to supply high-frequency current 29. The shielding 29 for all of the signal conductors 38 is electrically connected together by a common connector 43. I

The foul signal sets 23 each. comprise a typical amplifying circuit employing suitable amplifying tubes 44. The signal conductor 23 o each alley is connected to the input grid circuit of the first amplifier tube of the tubes 44 whereby the increase in voltage therefrom is greatly amplified. In actual practise, the tubes are biased to give a plate current cut-off when no one is in a fouling position so that when a foul is made, the increase in current in the plate circuit of the tubes increases from zero to the maximum for the given input signal. The plate output of each signal amplifying set is carried to its associated relay box 22 through suitable relay energizing leads 45. The relays may be mounted on the same chassis as the signal amplifiers, oscillator and power supplies.

and a secondary relay 41. The primary relay closes a contact 48 whichis in circuit with the solenoid of the secondary relay 41. and which is also in circuit with the signal bell 24 for that alley. Therefore the first result ofthc increased potential due to the commissionof a foul is to cause the primary relay to close thebell circuit and to actuate the secondary relay 41. The

latter closes a contact 49 in circuit with the foul indicating lamp 25 of that alley. The relay 41 is of the delayed opening type having an escapement or dash pot such as diagram'med at 50 which will hold the contact 49 closed after the supply contact 48 has opened. Thus, when a bowler leaves the fouling position, the bell will cease to operate but the lamp will remain illuminated for a preset interval. 7

Since the energizing plate I9 is connected to an earth ground at 32, and since one side of the secondary of the step-up transformer 42 is connected to the sheath of the signal conductor 28 while the other side of'the secondary is-connected to the negative of the plate supply, the metal chassis for the equipment in the oscillator amplifier will be above ground potential by the amount of voltage across the energizing transformer secondary. For this reason the chassis must be insulated from its metal cabinet. The cabinet however may be grounded to earth.

In some alleys, the side wall i4 is so close to the end alley that a foul may be committed by the bowlers hand on the wall. To indicate such fouls, the two pickup conductors at the end alley may be continued upward within or on the side wall I4, as indicated at 5|, so that any contact with the wall beyond the foul line, by the bowlers hand or body will give an audible and visible foul indication. ,1

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims,

without departing from the spirit of the inven- Each relay box contains a primary relay 7 energizing conductor positioned adjacent the bed "of the runway near said foul line; means for impressing a high frequency oscillating current on said energizing conductor so that the capacitative effect of the bowler'sbody' will transfer current from the energizing conductor to the pickup conductor; means for amplifying the current received by the pickup conductor; and means actuated by the amplified current for giving an '.rent received by the pickup conductor; a relay in circuit to be actuated by the amplified current, and a signal circuit closed by said relay.

AMES J. GLENDENNING. GEORGE S. DUNLAP. 

